Core drill



, l 1,634,506 July 51927 J. SMITCHELLI icona: DRILL I Filed 'April 50, 1924- 15 /15 L ,im O O O- Lf f s 1V 0, y

ldaterited duly i927.

' STATES PATEN OFFICE.

' JOSEPH S. MITCHELLOF CHICAGO, ILLINOS, ASSIGNOR TO SULLIVAN MACHINERY COMPANY, A CORPORATION 0F MASSACHUSETTS.

CORE DRILL.

My invention relatesto core drills.

An object of my invention is to provide an improved core lift'erfor such a drill. Another object of my invention isto provide an improved core lifter having `great elasticity and strength. A further and more specific object of my invention is toprov-ide an improved core lifter of great iiexibility and especially adapted to nse withl 'soft cores. These and other objects and advantages of my invention will, however, hereinafter -more fully appear.

In the accompanying drawings I have shown for purposes of illustration two forms which my invention may assume in practice.

In these drawings,-

Fig. l is a. central longitudinal sectional view through a core barrel and drill bit in which my improved core lifter-mechanism is incorporated, the section through the lifter being taken on line l-l of Fig. 2.

Fig. 2 is a plan view, partially broken away to facilitate illustration, of my improved core lifter.

Fig. 3 is a side elevation of Fig. 2.

Fig. l is an enlarged detail sectional vie-w showingy the spring holding means.

Fig. 5 is a detail sectional view of a modified form of construction.

In' the illustrative embodiment of my invention shown in Figs. l to 3,1 have shown a hollow core barrel l, of usual form, having a core lifter shell or casing 2 threaded thereto at its upper end, as at 3, While at its lower end it is threadedly. connected, as at 4, to a core drill bit 5 herein of the usual rotary diamond type, adapted to cut a core which passes up through a core lifter, generally designated 6, and of improved form hereinafter more fully described.

ln `my improved construction the core lifter, generally designated 6, comprises a' plurality of radially disposed wedge inembers 7 having vertical concave surfaces 8 which form an annular passage 9 through which the core is directed by means of inclined surfaces l0 formed on the lower inner edge of the wedge members. The outer periphery of eac-li of these wedges is also provided with a reduced portion ll in which a iiat sheet metal spring l2 shaped like a truncated cone and having great elasticity is disposed, the spring herein being rigidly held in place by rivets 13 and le. lt will the outer surfaces of the wedge members,

thereby forming a very rigid and compact construction in which the outer peripheries of the spring andthe wedges engage the walls of a conical bore 18 formed in the casing 2 inwhich the core lifter is disposed. It will also be observed that one of the Wedges and the spring member l2 are split as at 19 to permit free expansion and contraction of the core lifter. In the form of my invention shown in Fig. 5, I have shown the radiali eXpansible spring member l2 securely he d to wedges 2O by means of spot weldin instead of rivets, the spot welds being indicated herein at 21.

As a result of my improvement, it will be noted that a core lifter having great elasticity and strength is provided, and one which permits the ready passage of the core up through the same, while yet permitting the core lifter to rigidly grip even a. worn core.

While I have in this application specifically described two forms which my invention may assume in practice, it will be understood that these forms of the same are shown for purposes 'of illustration and that the invention maybe modied and embodied in other forms without departing from its spirit or the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent is:

l. A core lifter comprising separate spaced wedge shaped core engaging members having inclined external surfaces, a conical shaped split spring encircling said members,

and means for rigidly securing each of said members to said spring.

.- 2, A core lifter comprising separate spaced` 3. i core lifter comprising separate spaced wedge shaped core engaging members having inclinedenternal surfaces, a radially espansible tapered split spring encircling iio " cated cone shape disposed in said recesses,

and means for rigidly securing each of Said members to said spring.1

5. A core lifter comprising separate spaced wedge shaped core engaging members each having a projecting shoulder, a radially expansible conical shaped split spring, the shoulders on said members underlying the bottom edge of said spring, and means for rigidly securing each ofnsaid members to said spring.

6. A core 'having a projecting shoulder and inwardly inclined core guiding surfaces, a radially expansible conical shaped split spring, the shoulders on said Wedge members underlying the bottom edge of said spring, and means forrigidly securing each of said Wedge members to said s ring.

7 A core li er comprising separate spaced `Wedge shaped core engaging members each having apertures formed therein, said apertures having enlargedouter ends, la split resilient member having portions depressed into the enlarged portions of said apertures, and means including elements disposed in said' apertures for rigidly securing said Wedge members to said resilient member.

8. A core lifter comprising separate spaced Wedge shaped core engaging memlifter comprising separate spaced vwedge shaped core engaging members each .face, a split spring formed in the shape of a truncated cone and encircling Vsaid wedge members, and means for rigidly securing said spring to the outersurface of each of said Wedge shaped members.

10. Afr core lifter comprising separate spacedwedge shaped core engag1ngmem bers, each having a reduced outer surface and an outwardly lfprojecting shoulder, a split resilient member of truncated Acone sha e disposed against said reduced outer sur aces and engaging said shoulders, -and means for rigidly securing each Wedge shaped member to said resilient member.

11. A core lifter comprising a plurality of Wedge memberss a resilient member, arid means for securing said resilient member to said Wedges including a counterbore formed in said Wedges into which the surrounding metal of the resilient member is peened and means for riveting said resilient member therein. I

In testimony whereof I atiix my signature.

JOSEPH S. MITCHELL. 

